Scientists have grown a human embryo in a lab for a record breaking 13 days, in a breakthrough study which could revolutionise fertility treatment for thousands of women.

The human embryo survived in the lab for almost two weeks, which is double the previous record. Scientists are doing this research in the hope that it could shed light on the causes of miscarriage, genetic diseases, disabilities and infertility. Embryos which had previously been developed in the lab rarely make it past seven days without being implanted in the womb. It is unlikely that embryos intended to be implanted in patients will be kept in the lab for more than seven days in the near future, if at all.

Researchers at Cambridge University managed to grow the embryo the embryo for 13 days, choosing to stop before the 14 day legal limit. Until now, it has only been possible to study early-stage ‘blastocysts’, tiny balls of cells, during the few days prior to embryo attaching itself to the inner wall of the womb. The failure of an embryo to implant into the lining of has long been a major cause of infertility in many women.

Professor Zernicka Goetz, the leading scientist for this study from Cambridge University said: “Implantation is a milestone in human development as it is from this stage onwards that the embryo really begins to take shape and the overall body plan is decided. It is also the stage of pregnancy at which many developmental defects can become acquired. But until now, it has been impossible to study this in human embryos. This new technique provides us with a new opportunity to get deeper understanding of our own development during these crucial stages and help us understand what happens, for example, during miscarriage.”

As amazing as this treatment sounds, it does raise ethical questions; namely, how far can, or rather how far should, research scientists go?